From what I've gathered, where there's oil, there's natural gas. The ratio of oil and natural gas differs from reservoir to reservoir, so I understand, but the two are usually present together. 
Is that usually the case? Does presence of natural gas usually portend good chances of discovering oil?
Actually, natural gas is also recovered and sold. I have some land that produces about 300/month in royalties from natural gas. With the recent spike in natural gas prices and winter coming, I hope someone caps this well asap.
From what I've gathered, where there's oil, there's natural gas. The ratio of oil and natural gas differs from reservoir to reservoir, so I understand, but the two are usually present together.